This invention, named Trigrid(trademark), relates generally to the field of structural elements, and, more specifically, to concrete composite wall and floor systems utilizing a specific geometrical pattern of triangular ribs known as isogrid.
The isogrid pattern, as a proven concept, has been known to the aircraft industry for many years. Its origin is credited to famed British aircraft designer Barnes Wallis for its use in the Lancaster four engine heavy bomber which performed in World War II.
Formed out of machined metal alloys, isogrid has also been used in aerospace vehicle components in various forms such as the floor partition on the Skylab space station, the tank skin of the Saturn S-IV rocket and the Titan payload shroud. It was also adapted as the baseline structural concept for Rockwell""s space station payload interface. However, since the aerospace applications require special metal and highly sophisticated and costly machinery to manufacture, such applications have not been suitable for non-aerospace applications.
The isogrid structure employs upstanding ribs which are integral with a sheet material arranged in a series of abutting isosceles triangles. Some variations use equilateral triangles. Examples of the uses of isogrid structures is found in many patents, for example, U.S. Pat. Nos. 4,015,653, 4,116,258 and 4,141,872 entitled xe2x80x9cPanel Deployment Systemxe2x80x9d, xe2x80x9cPanel Deployment and Retraction Systemxe2x80x9d and xe2x80x9cPanel Deployment Systemxe2x80x9d, respectively, which issued on Apr. 5, 1977, Sep. 26, 1978 and May 1, 1979, respectively, to Slysh et al. disclose a panel of an extremely light isogrid structure comprised of a plurality of grid members arranged in a pattern of contiguous isosceles triangles and joined at their corners by circular nodes.
U.S. Pat. No. 3,940,891 entitled xe2x80x9cConical Structurexe2x80x9d which issued on Mar. 2, 1976 to Slysh is one of the early patents utilizing an isogrid reinforcing structure.
U.S. Pat. No. 4,012,549 entitled xe2x80x9cHigh Strength Composite Structurexe2x80x9d which issued on Mar. 15, 1977 to Slysh discloses a high strength composite structure utilizing an isogrid of equilateral triangles.
In the present construction industry, wood panels, typically plywood, are used to construct buildings and the like. Such wood panels typically require weather sealing by, for example, Tyvek(copyright) film, to prevent warpage and; the like in wet conditions. There are other disadvantages to the use of wood, ranging from the environmental concerns, the high cost of forest products and the need for columns and beam materials to provide support for the construction.
In contrast, concrete has been suggested as an alternative material for structural panels. For example, U.S. Pat. No. 5,566,520 entitled xe2x80x9cIntegrated Precast Concrete Forming Systemxe2x80x9d which issued on Oct. 22, 1996 to Branitzky shows precast concrete wall modules having reinforcing members and providing that the modules can be available in panels such as 8xc3x978, 8xc3x9716, etc.
U.S. Pat. No. 5,950,390 entitled xe2x80x9cPre-Cast Concrete Building Modulexe2x80x9d which issued on Sep. 14, 1999 to Jones provides a pre-cast concrete building module having reinforcing ribs and cavities to cause the module to be lighter.
U.S. Pat. No. 5,806,264 entitled xe2x80x9cMulti-Cellular Wall Structurexe2x80x9d which issued on Sep. 15, 1998 to Boot discloses a prefabricated reinforced wall structure having a concrete grid and having a layer of cement render on both sides. The render is a mixture of Portland cement and suitable aggregate and offers considerable bracing support for concrete grid 4 in the form of a surface skin that has significant compressive and in some case tensile capacities.
There have been some uses of isogrid panels in some construction uses. For example, U.S. Pat. No. 5,787,654 entitled xe2x80x9cIsogrid Tilexe2x80x9d which issued on Aug. 4, 1998 to Drost shows an isogrid tile of equilateral triangles which may be used for flooring assemblies.
U.S. Pat. No. 5,992,106 entitled xe2x80x9cHexagon Tile with Equilateral Reinforcementxe2x80x9d which issued on Nov. 30, 1999 to Carling et al. provide another tile for floor covering utilizing an isogrid of equilateral triangles.
U.S. Pat. No. 5,888,608 entitled xe2x80x9cComposite Grid/Frame Structuresxe2x80x9d which issued on Mar. 30, 1999 to Tsai discloses an isogrid element which may be used for concrete reinforcement. Col. 9, lines 5-7 mention that the reinforcing system is generic and can be applied to housing.
However, none of the known prior art disclose the combination set forth herein.
It is an object of this invention to provide a concrete composite, Trigrid structurale panel, for use in the construction industry.
It is an further object of this invention to provide a new lightweight structural panel that can be mass produced, easily transported to site and erected in place as a complete wall providing a method for attaching objects or panels such as drywall thereto.
It is still another object of this invention to provide a new improved structural panel which can be formed with a variety of finished exterior textures and colors ready to install.
It is yet another object of this invention to form such a panel in a curvature form so when attached together they would form a lightweight concrete tube or storage tank.
Further objects and advantages of the invention will become apparent as the following description proceeds and the features of novelty which characterize this invention will be pointed out with particularity in this specification.